A foundation composition can be applied to the face and other parts of the body to even skin tone and texture and to hide pores, imperfections, fine lines and the like. A foundation composition is also applied to moisturize the skin, to balance the oil level of the skin and to provide protection against the adverse effects of sunlight, wind and the harsh environment. Make-up compositions are generally available in the form of liquid or cream suspensions, emulsions, gels, pressed powders or anhydrous oil and wax compositions. Such cosmetic make-up compositions are described in U.S. Pat. Nos. 3,444,291, 4,486,405, 4,804,532, 3,978,207, 4,659,562, 5,143,722 and Nakamura et al., Preprints of the XIVth I.F.S.C.C. Congress, Barcelona, 1986, Vol. I, 51-63 (1986).
Foundations in the form of emulsions are well known and provide good coverage and good skin feel, wear and appearance. At the same time it would be desirable to provide a foundation composition having topical anti-acne activity. It would also be desirable to provide a foundation composition which is mild to the skin and which causes little or no skin irritation. There are many compounds which are known to exhibit anti-acne properties when applied topically to the skin. A commonly used kerotolytic agent having anti-acne activity is salicylic acid. As salicylic acid is virtually insoluble in water, it is difficult to incorporate into cosmetic compositions having an aqueous phase, such as emulsion compositions. Although salicylic acid can be delivered from the pigment-containing oil phase of a water-in-oil emulsion foundation composition for example, this can, however, lead to discolouration of the composition due to interaction between the salicylic acid and pigments, especially of the iron oxide type. It would therefore be desirable to deliver the salicylic acid in soluble form from cosmetic compositions having an aqueous phase.
Attempts have been made to improve the solubility of salicylic acid in aqueous phase. One way of doing this involves the use of alcohol solvents such as ethanol. However, such compositions can be harsh and can lead to skin irritation. Another way of helping to solubilise salicylic acid in aqueous systems involves the use of solubilising aids such as PVP. For example, WO 95/04517 discloses a make-up composition in the form of an emulsion comprising an acidic anti-acne active dissolved in the aqueous phase and a pigment or mixture of pigments dispersed in the oil phase. PVP is disclosed as a complexing agent for aiding the solubilisation of salicylic acid. Yet another way of helping to solubilise salicylic acid is by using cyclodextrin compounds. Cyclodextrin compounds are known to form inclusion complexes with salicylic acid which can aid solubilisation in aqueous systems. Ointment type compositions comprising cyclodextrin compounds and salicylic acid are known from the following documents: "Influence of cyclodextrins and other additives of the release of salicylic acid from various ointment bases", Yakuzaigaku, 50(4), 341-346 (1990) and "Effect of additives on release of drugs from ointment bases", Yakuzaigaku, 42(1), 10-16 (1982).
WO 95/31976 discloses a transdermal delivery system for anti-epileptic drug delivery comprising one or more permeation enhancers and a compound selected from tiagabine, its pharmaceutically acceptable salts, pharmaceutically-acceptable C.sub.1-6 -alkylesters or ionpairs of tiagabine and salicylic acid or oleic acid. The permeation enhancer can be selected from a group of permeation enhancers which includes hydroxypropyl-beta-cyclodextrin.
Despite being able to solubilise salicylic acid in the aqueous phases of cosmetic compositions using methods such as described above, there is still a need for cosmetic compositions having improved anti-acne/anti-inflammatory activity together with skin mildness/reduced skin irritation and improved product stability.
It has now been surprisingly found that by incorporating salicylic acid or a salicylic acid derivative and a hydroxy (C1-C4) alkyl cyclodextrin compound into an aqueous cosmetic composition comprising water there is provided a composition having improved anti-acne/anti-bacterial activity together with reduced skin irritation.
It is accordingly a primary object of this invention to provide a cosmetic composition having improved anti-acne activity.
It is also an object of the invention to provide a cosmetic composition having reduced skin irritation.
It is a further object of the invention to provide a cosmetic composition in the form of an emulsion having improved product stability.